Securely modifying exchange items in an exchange item marketplace network

摘要

A method begins with a server in a data communication system establishing an initial validity of an exchange item that includes data regarding a quantifiable value, a serial number, and issuance information, where the initial validity authenticates the exchange item and the data. The method continues with the server executing a secure custody protocol to establish that a first computing device has secure custody of the exchange item and to maintain validity of the exchange item. The method continues with the server transferring the secure custody of the exchange item from the first computing device to the server or to a second computing device. When the exchange item is in the secure custody of the server the method continues with the server modifying the data of the exchange item to produce a modified exchange item and transferring secure custody of the modified exchange item to the first computing device.